Re: access types and head pains

[Jeffrey Carter <jrcarter@acm.org>]

"chris.danx" wrote:
> 
> package X is
> 
>     type A is private
>     type A_ac is access all A;
> ...
> 
>     procedure Do_S (av : in out A_ac; v : any_type );
> 
>     --  with body
>     --    is begin
>     --        av.v := v; etc
> 
> end X;
> 
> procedure test is
>     at : aliased A;
> begin
>     Do_S (at'unchecked_access, 2);
> end test;
> 
> i got an error that said "at actual must be a variable".  What's wrong?
> 
> The idea is that the driver will work with two different kinda things in the
> same procedure.  "at" can be declared in program or be a chunk of memory of the
> same size. Any hints?

I suspect your message read "av actual ...". The parameter av is mode in
out, which means Do_S may modify it. You can't change
at'unchecked_access, because then it wouldn't be at'unchecked_access any
more. Unless you have "av := ...;" in Do_S, why not just make it mode
in?

-- 
Jeff Carter
"I waggle my private parts at your aunties."
Monty Python & the Holy Grail